阅读说明：本技术 一种耐渗流冲刷混凝土及其制备方法 (Seepage erosion resistant concrete and preparation method thereof ) 是由 李晓文 刘文燕 邢卫疆 孟玉冰 韩超 王振林 王延增 于海泉 于 2019-11-23 设计创作，主要内容包括：本发明公开了一种耐渗流冲刷混凝土及其制备方法。耐渗流冲刷混凝土包括以下组分：水泥、水、粉煤灰、硅灰、细骨料、粗骨料、外加剂、防腐剂、磨细矿粉；粗骨料包括质量比为1:(1.5-1.8)的花岗岩和玄武岩；外加剂包括质量比为1:(0.3-0.5):(0.5-0.7)的膨胀纤维抗裂防水剂、引气剂和减水剂；防腐剂包括以下重量份的原料：2-5份异丁基三乙氧基硅烷、1.2-1.6份桐油酸、0.8-1.6份硝酸钡、0.5-1份2BaO·SiO<Sub>2</Sub>和3-7份聚氨酯树脂。本发明的耐渗流冲刷混凝土具有耐海水渗流冲刷和耐腐蚀性能强,耐久性好的优点。(The invention discloses seepage erosion resistant concrete and a preparation method thereof. The seepage erosion resistant concrete comprises the following components: cement, water, fly ash, silica fume, fine aggregate, coarse aggregate, an additive, a preservative and ground mineral powder; the coarse aggregate comprises granite and basalt with the mass ratio of 1 (1.5-1.8); the additive comprises an expansion fiber anti-cracking waterproof agent, an air entraining agent and a water reducing agent with the mass ratio of 1 (0.3-0.5) to (0.5-0.7); the preservative comprises the following raw materials in parts by weight: 2-5 parts of isobutyl triethoxy silane, 1.2-1.6 parts of eleostearic acid, 0.8-1.6 parts of barium nitrate and 0.5-1 part of 2BaO SiO 2 And 3-7 parts of polyurethane resin. The seepage erosion resistant concrete has the advantages of seawater seepage erosion resistance andstrong corrosion resistance and good durability.)

1. The seepage erosion resistant concrete is characterized by comprising the following components in parts by weight: 400 parts of cement in 328-class, 185 parts of water in 155-class, 65-75 parts of fly ash, 45-65 parts of silica fume, 700 parts of fine aggregate in 670-class, 985 parts of coarse aggregate in 955-class, 12.2-14.5 parts of additive, 15.5-18.5 parts of preservative and 90-135 parts of ground mineral powder;

the coarse aggregate comprises granite and basalt in a mass ratio of 1 (1.5-1.8);

the additive comprises an expansion fiber anti-cracking waterproof agent, an air entraining agent and a water reducing agent in a mass ratio of 1 (0.3-0.5) to (0.5-0.7);

the preservative comprises the following raw materials in parts by weight: 2-5 parts of isobutyl triethoxy silane, 1.2-1.6 parts of eleostearic acid, 0.8-1.6 parts of barium nitrate and 0.5-1 part of 2BaO SiO₂And 3-7 parts of polyurethane resin.

2. The seepage scouring resistant concrete as claimed in claim 1, which comprises the following components in parts by weight: 346-382 parts of cement, 165-175 parts of water, 68-73 parts of fly ash, 50-55 parts of silica fume, 680-690 parts of fine aggregate, 865-975 parts of coarse aggregate, 13-13.9 parts of additive, 16.5-17.5 parts of preservative and 90-135 parts of ground mineral powder;

the coarse aggregate comprises granite and basalt in a mass ratio of 1: 1.65;

the additive comprises an expansion fiber anti-cracking waterproof agent, an air entraining agent and a water reducing agent in a mass ratio of 1:0.4: 0.6;

the preservative comprises the following raw materials in parts by weight: 3.5 parts of isobutyl triethoxy silane, 1.4 parts of eleostearic acid, 1.1 parts of barium nitrate and 0.8 part of 2BaO SiO₂And 5 parts of a polyurethane resin.

3. The seepage flush resistant concrete according to any one of claims 1-2, wherein the expansive fiber anti-cracking waterproof agent is prepared by the following method: according to parts by weight, 2-3.3 parts of coal gangue powder is calcined at the temperature of 1000-1200 ℃ for 30-50min, taken out, mixed with 1.2-1.8 parts of expanding agent, 2.5-3.5 parts of modified sepiolite powder and 1.1-1.5 parts of calcium oxide, crushed to prepare mixed powder with the granularity of 60-100 mu m, and then the mixed powder is mixed with 2.8-3.6 parts of PANI/PAN composite nano fiber and 1.6-2.4 parts of chitosan fiber and ground to prepare the expansion fiber anti-cracking waterproof agent with the granularity of 10-40 mu m.

4. The seepage scour resistant concrete according to claim 3, wherein the modified sepiolite powder is prepared by the following method: putting sepiolite powder into a calcium chloride solution with the concentration of 2mol/L, stirring for 1-2d at 40 ℃, carrying out suction filtration, washing with deionized water, drying, adding a silane coupling agent and absolute ethyl alcohol, carrying out water bath for 2-3h at 60 ℃, uniformly mixing, and drying to obtain the modified sepiolite powder, wherein the mass ratio of the sepiolite powder to the calcium chloride is 2:0.5-1, and the mass ratio of the sepiolite powder to the silane coupling agent to the absolute ethyl alcohol is 1:5-8: 6-10.

5. The seepage erosion resistant concrete as claimed in any one of claims 1-2, wherein the air entraining agent is prepared by mixing triterpenoid saponin with water, adding sodium thiosulfate, mixing uniformly, drying until the water content is lower than 1%, mixing with peach gum and crushing, the mass ratio of triterpenoid saponin to water is 1:2-3, and the mass ratio of triterpenoid saponin, sodium thiosulfate and peach gum is 1:0.4-0.6: 0.2-0.3.

6. The seepage erosion resistant concrete as recited in any one of claims 1-2, wherein the specific surface area of the ground ore powder is 374-474m²Per kg, mean particle size of silica fume 0.119. mu.m, SiO₂The content of the water reducing agent is 90-95%, and the water reducing agent is one of naphthalene sulfonate formal series high-efficiency water reducing agents and polycarboxylic acid high-efficiency water reducing agents.

7. The seepage erosion resistant concrete as claimed in any one of claims 1 to 2, wherein the fine aggregate is river sand with a fineness modulus of 2.5 to 3.0, and the mud content of the fine aggregate is less than or equal to 3%.

8. The seepage erosion resistant concrete as claimed in any one of claims 1-2, wherein the coarse aggregate is a composite of two gradations of 5-20mm and 20-40mm, the needle sheet content is less than or equal to 5%, the mud content is less than or equal to 0.5%, and the mud block content is less than or equal to 0.2%.

9. The seepage erosion resistant concrete as claimed in any one of claims 1-2, wherein the fly ash is class F class ii fly ash, the fineness (45 μm square mesh screen residue) is less than or equal to 12%, the water demand ratio is 95-98%, and the loss on ignition is less than or equal to 4.5%.

10. A method for preparing a concrete resistant to seepage erosion according to claims 1-9, comprising the steps of:

s1, uniformly mixing cement, coarse aggregate, fine aggregate, fly ash, silica fume and ground mineral powder to prepare a premix;

s2, adding the preservative and the additive into water, mixing uniformly and then adding into the premix to obtain the seepage erosion resistant concrete.

Technical Field

The invention relates to the technical field of building materials, in particular to seepage erosion resistant concrete and a preparation method thereof.

Background

Offshore areas of coastal cities are always golden sections of cities, more and more high-rise and super high-rise buildings are built along coastlines in Qingdao areas, Qingdao coastal areas have coastal foundations with good geological conditions, soft foundations such as miscellaneous filling soil and the like, and most of soil layers which are in contact with strongly weathered base rock surfaces and rich in water and strong in water permeability such as broken stones, gravel layers or medium and coarse sand form geological nonuniformity and complexity of Qingdao cities, so that geological nonuniformity and complexity are more obvious in coastal areas due to influence of seawater, damage to a coastal underground concrete structure has great concealment, the underground concrete structure is difficult to find and repair after being buried underground for a long time, potential safety hazards are great, the existing concrete research on coastal areas is prone to durability research such as corrosion resistance, and the like, the research on scouring resistance of concrete is concentrated on hydraulic concrete and pavement concrete, the research for seawater seepage scouring in the coastal region is less.

Disclosure of Invention

Aiming at the defects in the prior art, the first object of the invention is to provide seepage scouring resistant concrete which has the advantages of seawater seepage scouring resistance, strong corrosion resistance and good durability.

The second purpose of the invention is to provide a preparation method of seepage erosion resistant concrete, which has the advantages of simple preparation method and easy operation.

In order to achieve the first object, the invention provides the following technical scheme: the seepage erosion resistant concrete comprises the following components in parts by weight: 400 parts of cement in 328-class, 185 parts of water in 155-class, 65-75 parts of fly ash, 45-65 parts of silica fume, 700 parts of fine aggregate in 670-class, 985 parts of coarse aggregate in 955-class, 12.2-14.5 parts of additive, 15.5-18.5 parts of preservative and 90-135 parts of ground mineral powder; the coarse aggregate comprises granite and basalt in a mass ratio of 1 (1.5-1.8);

the additive comprises an expansion fiber anti-cracking waterproof agent, an air entraining agent and a water reducing agent in a mass ratio of 1 (0.3-0.5) to (0.5-0.7); the preservative comprises the following raw materials in parts by weight: 2-5 parts of condensed aluminum phosphate, 1.2-1.6 parts of eleostearic acid, 0.8-1.6 parts of water glass and 0.5-1 part of 2BaO SiO₂And 3-7 parts of polyurethane resin.

By adopting the technical scheme, after the fly ash, the silica fume, the ground mineral powder and the like are doped into the concrete, the active ingredients of the fly ash, the silica fume, the ground mineral powder and the like perform secondary reaction with calcium hydroxide in the cement to generate hydrated calcium silicate gel with higher strength and better stability, so that the composition of gelled substances in the concrete is improved, the performance of a concrete interface structure and an interface area is improved, and the generated products are filled in pores inside the concrete, so that the effect of closing through holes is achieved, the porosity is reduced, and the compressive strength and the impermeability of the concrete are improved; granite has compact structure, hard texture, acid and alkali resistance, good compression resistance and wear resistance of basalt and low water absorption, and the hardness of concrete can be improved by using the basalt and the coarse aggregate in a matching way, so that the wear resistance and the scouring resistance of the concrete are enhanced.

The expansion fiber anti-cracking waterproof agent, the air entraining agent and the water reducing agent are used as additives, the expansion fiber anti-cracking waterproof agent generates a large amount of ettringite in the hydration process to block capillary channels of concrete, so that the concrete structure is more compact, the impermeability of the concrete is improved, fiber components contained in the expansion fiber anti-cracking waterproof agent have better elastic modulus, the crack resistance, the wear resistance and the high impact resistance of the concrete can be improved, the air entraining agent can reduce the permeability of the concrete and reduce the bleeding amount, a large amount of micro bubbles in concrete slurry can block or block capillary water seepage channels of the concrete, the pore structure of the concrete is improved, so that the impermeability of the concrete is improved, the water reducing agent can be adsorbed on the surfaces of particles to increase the mutual repulsion between the particles, so that cement particles are dispersed, water wrapped by flocculating constituents is released, the purpose of reducing the water is achieved, and the viscosity of the cement slurry is, the fluidity is improved, and the three are mutually matched, so that the impermeability, the crack resistance and the wear resistance of the concrete can be improved.

The condensed aluminum phosphate and the sodium silicate are used in the preservative, the hardened concrete can be subjected to surface treatment, capillary channels of a concrete structure can be sealed, silicic acid particles separated out from the sodium silicate and filled in the capillary channels react with calcium hydroxide serving as a hydration product of cement to generate C-S-H gel which is more favorable for improving impermeability and durability, aluminum oxide in the polymerized aluminum phosphate can react with the calcium hydroxide to generate hydrated calcium aluminate, the effect of improving surface density and hardness is achieved, the polymerized aluminum phosphate can also solidify sodium ions separated out from the sodium silicate, and the water resistance of the surface layer of the concrete is improvedTherefore, the polymerized aluminum phosphate and the water glass have synergistic effect, and the impermeability and the scouring resistance of the hardened concrete can be enhanced; eleostearic acid has waterproof, acid and alkali resistant, anticorrosive and antirust effects, and can delay 2BaO SiO₂The hydration speed of (1) is high, the reaction of gypsum and Ba0 is avoided, the normal coagulation of cement is influenced, Ba0 reacts with sulfate ions permeating into concrete to generate almost insoluble mixture-barium sulfate, the structure of the cement is more compact, and meanwhile, the reaction of generating ettringite is also avoided, so that the sulfate corrosion resistance of the concrete is improved, the wear resistance of the concrete is enhanced, the polyurethane resin is a film-forming substance, a curing film with acid and alkali resistance and corrosion resistance can be formed in the concrete structure, the strength, crack resistance and wear resistance of the concrete are improved, and the corrosion resistance of the concrete is enhanced.

Further, the paint comprises the following components in parts by weight: 346-382 parts of cement, 165-175 parts of water, 68-73 parts of fly ash, 50-55 parts of silica fume, 680-690 parts of fine aggregate, 865-975 parts of coarse aggregate, 13-13.9 parts of additive, 16.5-17.5 parts of preservative and 90-135 parts of ground mineral powder;

the coarse aggregate comprises granite and basalt in a mass ratio of 1: 1.65;

the additive comprises an expansion fiber anti-cracking waterproof agent, an air entraining agent and a water reducing agent in a mass ratio of 1:0.4: 0.6;

the preservative comprises the following raw materials in parts by weight: 3.5 parts of condensed aluminum phosphate, 1.4 parts of eleostearic acid, 1.1 parts of water glass and 0.8 part of 2BaO SiO₂And 5 parts of a polyurethane resin.

By adopting the technical scheme, the dosage of each component in the seepage scouring resistant concrete is more accurate, so that the prepared concrete has high surface hardness, good compactness, strong impermeability and good seepage scouring resistance.

Further, the anti-cracking waterproof agent for the expanded fibers is prepared by the following method: according to parts by weight, 2-3.3 parts of coal gangue powder is calcined at the temperature of 1000-1200 ℃ for 30-50min, taken out, mixed with 1.2-1.8 parts of expanding agent, 2.5-3.5 parts of modified sepiolite powder and 1.1-1.5 parts of calcium oxide, crushed to prepare mixed powder with the granularity of 60-100 mu m, and then the mixed powder is mixed with 2.8-3.6 parts of PANI/PAN composite nano fiber and 1.6-2.4 parts of chitosan fiber and ground to prepare the expansion fiber anti-cracking waterproof agent with the granularity of 10-40 mu m.

By adopting the technical scheme, the modified sepiolite powder has good adsorption effect, can enable PANI/PAN composite nano fibers and chitosan fibers to be mutually wound in concrete, has good mechanical properties and high elastic modulus, and can enhance the crack resistance and the impermeability of the concrete under the matching action of coal gangue powder and the like.

Further, the modified sepiolite powder is prepared by the following method: putting sepiolite powder into a calcium chloride solution with the concentration of 2mol/L, stirring for 1-2d at 40 ℃, carrying out suction filtration, washing with deionized water, drying, adding a silane coupling agent and absolute ethyl alcohol, carrying out water bath for 2-3h at 60 ℃, uniformly mixing, and drying to obtain the modified sepiolite powder, wherein the mass ratio of the sepiolite powder to the calcium chloride is 2:1-0.5, and the mass ratio of the sepiolite powder to the silane coupling agent to the absolute ethyl alcohol is 1:5-8: 6-10.

By adopting the technical scheme, the sepiolite powder is soaked by calcium chloride and then mixed with the silane coupling agent and the absolute ethyl alcohol, so that the sepiolite powder has better adsorbability and dispersibility, can adsorb PANI/PAN composite nano fibers and chitosan fibers, the two fibers are mutually wound, the modified sepiolite powder forms a net structure in concrete, the holding power of the two fibers in the concrete is enhanced, and the anti-cracking performance of the concrete is improved.

Further, the air entraining agent is prepared by mixing triterpenoid saponin with water, adding sodium thiosulfate, uniformly mixing, drying until the water content is lower than 1%, mixing with peach gum and crushing, wherein the mass ratio of the triterpenoid saponin to the water is 1:2-3, and the mass ratio of the triterpenoid saponin to the sodium thiosulfate to the peach gum is 1:0.4-0.6: 0.2-0.3.

By adopting the technical scheme, the peach gum has good adsorbability, can be used for adsorbing large-particle artificial aggregates and preventing large-particle aggregates from generating pores in concrete slurry, the triterpenoid saponin has the characteristics of strong dispersibility and good water property, can improve the surface tension of the concrete and improve the durability of the concrete, the sodium thiosulfate has a certain plasticizing effect on the concrete, and has an early strength effect, the compressive strength of the concrete can be enhanced, and the wear resistance of the surface of the concrete can be improved.

Further, the specific surface area of the ground ore powder is 374-474m²Per kg, mean particle size of silica fume 0.119. mu.m, SiO₂The content of the water reducing agent is 90-95%, and the water reducing agent is one of naphthalene sulfonate formal series high-efficiency water reducing agents and polycarboxylic acid high-efficiency water reducing agents.

By adopting the technical scheme, the larger the specific surface area of the ground mineral powder is, the larger the fluidity of the slurry is, the more the water is adsorbed, the more the surface active particles are, the higher the hydration speed of the mineral powder is, and the specific surface area is 374-474m²The shape of each kg of mineral powder particles is closer to a spherical shape, the spherical particles are not easy to be mutually overlapped, the aggregation structure formed in slurry is less, and the flowability of the slurry is better; the silica fume particles can be filled in the gaps of the particles which are tightly piled up, the micro powder effect is exerted, the piling density is improved, the silica fume has huge specific surface area, the activity of the volcanic ash is extremely high, the high-activity silica reacts with calcium hydroxide generated by the hydration of clinker to generate C-S-H gel, the volume density of concrete can be further improved, the apparent porosity is reduced, the compressive strength is increased, the water demand is obviously increased due to the huge specific surface area of the silica fume, therefore, a high-efficiency water reducing agent needs to be introduced, the fluidity of concrete slurry is adjusted, meanwhile, the high-efficiency water reducing agent has certain promotion effect on the hydration of cement, the naphthalene sulfonate formal high-efficiency water reducing agent can be adsorbed on the surfaces of the particles, the mutual repulsion effect among the particles is increased, the cement particles are promoted to be dispersed, and the water wrapped by a flocculating constituent is released, so as, the viscosity of the cement paste is reduced and the fluidity is improved.

Furthermore, the fine aggregate is river sand with fineness modulus of 2.5-3.0, and the mud content of the fine aggregate is less than or equal to 3%.

By adopting the technical scheme, the river sand has high hardness and good wear resistance, and the content of clay and other harmful impurities is low, so that the scouring resistance of the concrete is good, the fineness modulus is proper, the concrete has better workability, the construction workability is good, the stirring is easy, the concrete can be filled in the pores among the coarse aggregates, the compactness and the strength of the concrete are improved, the porosity in the concrete is reduced, the segregation and bleeding of the concrete are reduced, and the strength of the concrete is improved; the coarse aggregate has proper content of needle-shaped particles, can effectively improve the strength of concrete, avoids larger particles, enables pores among aggregates to be larger, causes lower strength of the concrete, forms reasonable gradation with fine aggregates, fly ash and ground mineral powder, and can improve the compactness of the concrete, thereby improving the crack resistance and the impermeability of the concrete.

Furthermore, the coarse aggregate is a composite of two gradations of 5-20mm and 20-40mm, the needle sheet content is less than or equal to 5%, the mud content is less than or equal to 0.5%, and the mud block content is less than or equal to 0.2%.

By adopting the technical scheme, the content of the needle-shaped particles in the coarse aggregate is proper, the strength of the concrete can be effectively improved, the situation that the particles are large and the pores among the aggregates are large to cause low strength of the concrete is avoided, the particles, the fine aggregate, the fly ash and the ground mineral powder form reasonable grading, the compactness of the concrete can be improved, and the crack resistance and the impermeability of the concrete are improved.

Further, the fly ash is F-class II-grade fly ash, the fineness (the screen residue of a 45-micrometer square-hole screen) is less than or equal to 12 percent, the water demand ratio is 95-98 percent, and the ignition loss is less than or equal to 4.5 percent.

By adopting the technical scheme, the active ingredients of the fly ash are silicon dioxide and aluminum oxide, and after the fly ash is mixed with a cement hydration product, a stable cementing material can be generated, so that the concrete has higher strength, meanwhile, more than 70% of particles in the fly ash are amorphous spherical glass bodies and mainly play a role of a ball bearing, a lubricating effect is exerted in the concrete mixture, the workability of the concrete mixture is improved, the fly ash and coarse aggregate and the like form reasonable grading, the fly ash and the coarse aggregate are mutually filled, the compactness of the concrete can be effectively increased, the compressive strength of the concrete is further improved, and the concrete structure is compact and is not easy to seep water and crack.

In order to achieve the second object, the invention provides the following technical scheme: a preparation method of seepage erosion resistant concrete comprises the following steps:

s1, uniformly mixing cement, coarse aggregate, fine aggregate, fly ash, silica fume and ground mineral powder to prepare a premix;

s2, adding the preservative and the additive into water, mixing uniformly and then adding into the premix to obtain the seepage erosion resistant concrete.

In conclusion, the invention has the following beneficial effects:

firstly, because the granite is adopted as the coarse aggregate, the granite has compact structure, hard texture, acid and alkali corrosion resistance, the basalt has good wear resistance and small water absorption rate, the hardness and the compressive strength of the hardened concrete are improved by matching the granite and the basalt, the scouring resistance and the wear resistance of the concrete are improved, the fly ash, the silica fume and the ground mineral powder can generate hydrated calcium silicate gel with high strength and good stability, the hydrated calcium silicate gel can be filled in the pores of the concrete, the porosity is reduced, the impermeability and the compressive strength are improved, and multiple components are cooperatively used, so that the seepage scouring resistance, the impermeability and the corrosion resistance of the concrete are improved.

Secondly, the expansion fiber anti-cracking waterproof agent, the air entraining agent and the water reducing agent are preferably adopted to be matched to be used as additives, the expansion fiber anti-cracking waterproof agent can enable the structure of the concrete to be more compact and increase the anti-cracking, impact resistance and wear resistance of the concrete, the air entraining agent can improve the pore structure of the concrete, block a capillary water seepage pore passage and improve the anti-cracking performance of the concrete, and the water reducing agent can promote the cement particles to be dispersed, reduce the viscosity and improve the fluidity, and can improve the anti-permeability, wear resistance and crack resistance of the concrete under the synergistic effect of the three components.

Thirdly, in the invention, the hardened concrete is preferably subjected to surface treatment by using a preservative containing condensed aluminum phosphate, water glass, eleostearic acid and the like, the water glass can generate C-S-H gel for improving impermeability and durability with a hydration product of cement, the polymerized aluminum phosphate can cure sodium ions separated out from the water glass, the water resistance is improved, eleostearic acid has the effects of water resistance, acid and alkali resistance, corrosion resistance and rust resistance, and 2BaO & SiO can be delayed₂The hydration speed of the concrete is high, BaO can be combined with sulfate ions, so that the concrete structure is more compact, and the sulfate corrosion resistance of the concrete is improved.

Fourth, the invention preferentially uses PANI/PAN composite nanofiber and chitosan fiber and other raw materials to prepare the expansive fiber anti-cracking waterproof agent, the PANI/PAN composite nanofiber and the chitosan fiber have good anti-cracking and anti-corrosion effects, the PANI/PAN composite nanofiber and the chitosan fiber are mutually wound in concrete under the action of the modified sepiolite, and the anti-cracking, anti-corrosion and anti-permeability of the concrete can be enhanced by matching with coal gangue powder and calcium oxide.

Detailed Description

The present invention will be described in further detail with reference to examples.

Preparation examples 1 to 3 of expansive fiber anticracking waterproof agent

The swelling agent in preparation examples 1 to 3 was selected from swelling agents sold by Shandong Lujie New building materials Co., Ltd, having a product number of D548551, the silane coupling agent was selected from silane coupling agents sold by Jinan Huanyang chemical Co., Ltd, having a product number of KH172, and the chitosan fiber was selected from chitosan fibers sold by Qingdao instant Megaku Co., Ltd, having a product number of JF-100-F.

Preparation example 1: calcining 2kg of coal gangue powder at 1000 ℃ for 50min, taking out, mixing and crushing the calcined coal gangue powder, 1.2kg of expanding agent, 2.5kg of modified sepiolite powder and 1.1-1.5kg of calcium oxide to prepare mixed powder with the granularity of 60um, mixing and grinding the mixed powder, 2.8kg of PANI/PAN composite nano fiber and 1.6kg of chitosan fiber to prepare the expanded fiber anti-cracking waterproof agent with the granularity of 10 mu m, wherein the modified sepiolite is prepared by the following method: putting sepiolite powder into a calcium chloride solution with the concentration of 2mol/L, stirring for 1d at 40 ℃, carrying out suction filtration, washing with deionized water, drying, adding a silane coupling agent and absolute ethyl alcohol, carrying out water bath for 2h at 60 ℃, mixing uniformly, and drying to obtain modified sepiolite powder, wherein the mass ratio of the sepiolite powder to the calcium chloride is 2:1, and the mass ratio of the sepiolite powder to the silane coupling agent to the absolute ethyl alcohol is 1:5: 6; the PANI/PAN composite nano-fiber is prepared by mixing N, N-dimethylformamide with polyaniline, then mixing with DMF (dimethyl formamide) solution of polyacrylonitrile to prepare a PAIN/PAN composite dispersion system, and performing electrostatic spinning.

Preparation example 2: calcining 2.6kg of coal gangue powder at 1100 ℃ for 40min, taking out, mixing and crushing the calcined coal gangue powder, 1.5kg of expanding agent, 3kg of modified sepiolite powder and 1.3kg of calcium oxide to prepare mixed powder with the granularity of 80um, mixing and grinding the mixed powder, 3.2kg of PANI/PAN composite nano fiber and 2kg of chitosan fiber to prepare the expanded fiber anti-cracking waterproof agent with the granularity of 25 mu m, wherein the modified sepiolite is prepared by the following method: putting sepiolite powder into calcium chloride solution with the concentration of 2mol/L, stirring for 2d at 40 ℃, carrying out suction filtration, washing with deionized water, drying, adding a silane coupling agent and absolute ethyl alcohol, carrying out water bath for 2.5h at 60 ℃, uniformly mixing, and drying to obtain modified sepiolite powder, wherein the mass ratio of the sepiolite powder to the calcium chloride is 2:0.8, the mass ratio of the sepiolite powder to the silane coupling agent to the absolute ethyl alcohol is 1:6.5:8, the PANI/PAN composite nano-fiber is prepared by mixing polyaniline with N, N-dimethylformamide, then mixing with DMF solution of polyacrylonitrile to prepare a PAIN/PAN composite dispersion system, and carrying out electrostatic spinning to obtain the PAIN/PAN composite dispersion system.

Preparation example 3: calcining 3.3kg of coal gangue powder at 1200 ℃ for 30min, taking out, mixing and crushing the calcined coal gangue powder, 1.8kg of expanding agent, 3.5kg of modified sepiolite powder and 1.5kg of calcium oxide to prepare mixed powder with the granularity of 100um, mixing and grinding the mixed powder, 3.6kg of PANI/PAN composite nano fiber and 2.4kg of chitosan fiber to prepare the expanded fiber anti-cracking waterproof agent with the granularity of 40 mu m, wherein the modified sepiolite is prepared by the following method: putting sepiolite powder into calcium chloride solution with the concentration of 2mol/L, stirring for 2d at 40 ℃, carrying out suction filtration, washing with deionized water, drying, adding a silane coupling agent and absolute ethyl alcohol, carrying out water bath for 3h at 60 ℃, uniformly mixing, and drying to obtain modified sepiolite powder, wherein the mass ratio of the sepiolite powder to the calcium chloride is 2:0.5, the mass ratio of the sepiolite powder to the silane coupling agent to the absolute ethyl alcohol is 1:8:10, the PANI/PAN composite nanofiber is prepared by mixing N, N-dimethylformamide polyaniline, and then mixing with DMF solution of polyacrylonitrile to prepare a PAIN/PAN composite dispersion system, and the PAIN/PAN composite dispersion system is prepared by electrostatic spinning.